Breaking leaf springs

Is that a conventional undersprung (spring pack beneath axle) or an over axle conversion to gain more ground clearance?
mike

Which ever style of spring mount it is, the problem indicates that the spring pad area is not long enough to hold the spring securely AND provide an inert area tightly clamped to the axle so the centre of the spring around the centre bolt cannot flex/isn't being flexed.
The ONLY reason it will break there, is if there is a deficiency in the clamped area/support.

Although different, same technology, the length, ie front to back of that area on a dual cab ute is at least 120mm long. on trailers and caravans I have seen far less length of the spring support and that WILL allow the centre of the spring leaf to flex and it will surely break.

Poor design if breaking there.

hi
Poor quality manufacture or springs that have been reset more than once have high failure rate .
broken leaves ,broken centre bolts ,broken or loose spring clamps
Springs would not last longer than 3mths
New springs would allways last the longest Australian steel ,Australian made by a recognized maker .Even a poor quality steel works can still stuff it up, if having poor process
The different opinions of manufacturing process does lead to large variations in durability
This experience was from underground 4x4 utes patrol and cruiser .
swampy.
That was 20 yrs ago

We have a 21.6 Traveller as well. It is now 5 yo and has the Road runner chassis. We broke a leaf in the right rear spring last year. It was one of the lower leaves and presented no real hazard.

I replaced both springs on that axle with parts from my local supplier of trailer parts. I check the undercarriage before every trip and have seen no further issues. I did retension all the U bolts to be sure all was tight.

The van has done approx 50,000km since new.

frank

is the van within its weight limits???????????

If all these vans are of about the same vintage I wonder if there was a bad batch of springs, either with the material or the tempering process. The other possibility, as has been stated is incorrect original tensioning of the U bolts. Even faulty U bolt material allowing them to loose their tension.

Cheers
Pop

One thing that must be remembered ...... pretty much all light trailer parts are crap in comparison to that you would find on any passenger car or light commercial.

The springs are of no where near the quality you would fund under the back of your tow vehicle ..... and the suspension designes are crude.

the axle pads and fish plates leave a lot to be desired ...... in geneeral the axle pads are too small and do not have curved edges as you would find on a similar car spring ...... many times the springpads are not even fixed to the axle..... they just sit there by friction and good luck...... the fishplates likewise are just a square of plate with pretty wide tolerances in the holes ...... and the U bolts just dont compare to those from the major vehicle manufacturers ........ and they are in general assembled in envoronments with far poorer qulaity control.

So don't be surprised that you find spring breakages on caravans and trailers .... no matter the price. ... this is an all too common failing

As has been mentioned IF the main sprinf leaf is breaking thru the middle .... this does indicate the spring pack is not properly clamped and supported. ..... there should be no flexing in the centre square of the spring pack.

If you care and if it matters to you, you can improve this by.

making and fitting larger spring pads, of thicker material, grinding a curve on the edges rather than leaving a sharp edge and making sure it is positivly located.

Making up heavier and correctly shaped fish plates that are accurately drilled and have holes not considerably oversized for the u bolts.

Make sure the pads and fishplates are reasonably flat with no lumps bumps or burs.

buying good quality U bolts of the correct size and length ...... fitting them with high tensile plain washers and high tensile nuts and then either use a second nut as a lock nut or a nylock nut as a lock nut ...... AND grease your threads .... any grease will do, never seaze is better.

when you assemble ..... be fussy ..... before you start make sure evrything is flat and smooth ....... make sure everything is aligned straight and central.

and those U bolts need to be evenly tightened and they do need to be pretty tight. ...... hell if you have one use a torque wrench ....... note that most trailer U bolts have coarser threads than the car manufacturers use ..... so you have to cranke em up harder to achieve the same bolt tension.

Because of the crappiness of the materials you need to be a bit fussier to get reliability.

hope this helps.
cheers